Self-cleaning screen device



Feb. 19, 1957 Filed June 22, 1954 J. J. COLEMAN SELF-CLEANING SCREEN DEVICE 2 Sheets-Sheet 1 INVENTOR. M44453 (1 COLEMAN ATTORNEYS.

Feb. 19, 1957 J. J. COLEMAN 2,731,916

- SELF-CLEANING SCREEN DEVICE Filed June 22, 1954 2 Sheets-Sheet 2 IN VEN TOR. dA MES d. C OL EMA N BY A TTOR/VEYS.

United States ,Patent SELF-CLEANING SCREEN DEVICE James J. Coleman, Stroudsburg, Pa., assignor to The I, Patterson-Kelley Co., Inc., East Stroudsburg, Pa.

Application June 22, 1954, Serial No. 438,410 3 Claims. (Cl. 210-152) This invention relates to industrial screening devices, and more particularly for an improved arrangement for keeping screen-plugging materials in industrial liquids from clogging screen openings. The invention is particularly useful in conjunction, for example, with commercial laundry Waste-water screening devices, because it solves the usual problem of laundry lint clogging, such as has heretofore been extremely troublesome in the case of conventional screening devices for such purposes.

In the drawing:

Fig. 1 is a fragmentary plan view of a commercial laundry waste water screening and reclaiming system, employing a waste water screening device of the present invention;

Fig. 2 is a side elevation and sectional view thereof;

Fig. 3 is a fragmentary vertical sectional view through the screening device of the present invention; and

Fig. 4 is a fragmentary section on enlarged scale taken along line IV-IV of Fig. 3.

As shown in Figs. 1 and 2, the screen device of the invention may be employed in conjunction with a system for reclaiming waste water, such as from a commercial laundry. The system shown includes a waste water conveying gutter as indicated at 10, such as conventionally includes a set of screen plates as indicated at 12 for preliminary screening of the waste water. After the water from the gutter flows through the screens 12 it passes downwardly into a sump 14 from whence it is arranged to be picked up by the suction pipe 15 of a pump 16 for delivery into any suitable type reclaimer as indicated at 18.

In accord with the present invention, the intake conduit for the pump 16 is arranged to terminate in a lower suction end portion 20 which extends vertically downwardly into a revolving basket type screen 21 comprising a closed bottom, an open top cylinder having cylinder side wall 22 perforated such as indicated at 24 and a solid or perforated bottom plate as indicated at 26. The screen device 21 may be conveniently mounted by means of a vertical central shaft 28 carried by a pedestal bearing 29 (supported from an adjacent wall structure of the sump 14), the upper end of the shaft 28 being coupled as indicated at 30 to a drive shaft 32 extending from a motor as indicated at 34. Triangularly shaped plates 36-38-40 are provided such as integrally with a sleeve 42 which telescopically fits over the lower end of the drive shaft 28 and is rigidly fixed thereto; the lower ends of the plates 36-38-40 being connected to the bottom plate 26 of the screen device; thereby rigidifying the screen device relative to the drive shaft 28. Also, the plates 36-38-40 function to assist in the screen clearing operation, as will be explained more fully hereinafter.

Externally of the cylindrical side wall structure 22 a stationary scraper device as indicated at 44 is mounted as by means of a bracket 46 to extend from a primary bracket plate 48 which also conveniently mounts the pedestal bearing 29 and the pump intake or suction conduit 20. The plate 48 is in turn rigidly mounted against the side wall structure of the sump. 14 so that the screen 22 is thereby supported at an elevation so as to be substantially submerged in the liquid in the sump, the top of which will approximate a level as indicated at 50 in Figs. 2-3.

It is a particular feature of the present invention that the plates 36-38-40 disposed internally of the screen and rotating therewith cooperate with the stationary conduit 20 which is disposed inside of the screen in relatively close proximity to the position of the scraper 44 externally thereof (Fig. 4). It has been determined'that this particular relative arrangement of scraper plate and stationary intake pipe and rotating bafile plates sets up a unique liquid flow pattern and turbulence internally of the screen device which operates to prevent permanent plugging by lint accumulations or the like of the pores 24 of the screen coincidental with scraping away of larger accumulations of solids from the exterior side wall surfaces of the screen by opera-tion of the scraper 44. It appears that as each bafile plate rotates toward the stationary intake pipe 20 it drives a body of liquid ahead of it and against the pipe which then causes the body of liquid to divide into two streams of fluid passing around opposite sides of the pipe. This action sets up pressure and fluid flow velocity differentials fore and aft of the pipe 20; one stream of liquid being funneled into the constricted space between the pipe and the screen shell. This action is of course intermittent, and therefore the pressure force and liquid flow variations occur in constantly changing patterns within the channel defined between the stationary pipe 20 and the side wall of the screen in the neighborhood of the scraper 44.

Thus, it will be appreciated that by reason of the novel construction of the screen device of the invention, the plates 36-38-4-0 perform dual functions of bracing the screen relative to its support shaft and driving bodies of fluid against the stationary pipe 20. Furthermore, the centrifugal forces developed by rapid rotation of the screen as well as the intermittent surges and flows of liquid through the channel between the pipe 20 and the screen wall in the neighborhood where the scraper keeps the external layer of solids to a minimum forestalls the usual tendency of solids such as lint in the incoming liquid to plug the screen apertures in improved manner. As shown in Figs. 3-4, the bottom end of the intake pipe 20 is preferably partially closed off as indicated at 52, and the inner corner portion thereof is chamfered as indicated at 54 so as to permit liquid to be drawn into the lower end of the pipe while permitting the triangularly shaped bafile plates 36-38-40 to rotate more closely adjacent the bottom end of the pipe 20 without interferences therebetween.

It will of course be appreciated that whereas only one form of the invention has been shown and described in detail, it will be apparent to those skilled in the art that the invention is not so limited but that various changes may be made therein without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A screen for cleaning liquids having accumulations of lint or the like therein, comprising a basket type screen adapted to be disposed within a sump in at least partially submerged relation in the liquid therein, a debris scraper disposed externally of said screen arranged to scrape solids accumulations therefrom as the screen rotates, a pump intake conduit extending into said screen for withdrawing screened liquid therefrom, the intake end portion of said conduit being disposed adjacent a rotating side wall portion of said screen in the region ofsaid scraper device, and a baflle plate device carried internally of said screen and rotatable therewith periodically into the region of the intake end portion of said conduit for impelling the liquid interiorly of said screen against said conduit and Patented Feb. 19, 1957:

against the screen side wall in the region of said scraper device. incidental to. rotation of saidtscreen.

2. In a circulating liquid system, a sump into which the liquid flows, a pump for withdrawing the liquid from said. sump,: a rotating cylindrical screen having a closed imperforate bottom disposed to rotate about a neutral axis, withinsaid. sump at least partially submerged in the liquid-therein, a debris scraper stationarily disposed externally of said screen cylinder. wall in,.scraping relation thereagainst as the screen rotates, a pump intake conduit comprising a stationarily disposed substantially rigid pipe extending into said screen from above for withdrawing screen'filtered liquid therefrom, said conduit being disposed to extend adjacent a rotating side wall portion of saidscreen in the region of said scraper device, and a bafile plate carried internally of said screen and rotatable therewith periodically into the region of said conduit for pulsing the liquid internally of said screen into the channel between said conduit and the screen side wall in the region of said scraper device incidental to rotation of said screen.

3. A screen for cleaning liquids having accumulations of lint or the like therein, comprising a basket type screen mounted to rotate about a vertical axis and disposed within a sump in at least partially submerged relation in the liquids therein, a debris scraper disposed externally of said screen arranged to scrape solids accumulations therefrom as the screen rotates, a pump intake conduit extending into said screen for withdrawing screened liquid therefrom, said conduit being disposed to extend adjacent the rotating side wall portion of said screen in the region of said scraper device, and a bafiie plate device carried internally of said screen and rotatable therewith periodically into the region of said conduit for impelling the liquid interiorly of said screen to pulse against said conduit and against the screen side wallin the region of said scraper device incidental to rotation of said screen.

References Cited in the file of this patent UNITED STATES PATENTS 1,219,290 Goyne Mar. 13, 1917 1,274,121 White July 30, 19.18 1,421,440 Fisher July 4, 1922 1,611,739 Hadfield Dec. 21, 1926 2,362,750 Hayward Nov. 14, 1944 2,540,474 COX Feb. 6, 1951 

